Add deriving Show to various data types

Mostly for better debugging.

lib/ghcitui-brick/Ghcitui/Brick/AppConfig.hs

@@ -43,7 +43,7 @@ data AppConfig = AppConfig
     -- ^ Command to run to initialise the interpreter.
     , getStartupCommands :: ![T.Text]
     -- ^ Commands to run in ghci during start up.
-    }
+    } deriving (Show)
 
 defaultConfig :: AppConfig
 defaultConfig =

lib/ghcitui-brick/Ghcitui/Brick/AppInterpState.hs

@@ -32,7 +32,7 @@ data AppInterpState s n = AppInterpState
     , _cmdHistory :: ![[s]]
     , historyPos :: !Int
     -- ^ Current position
-    }
+    } deriving (Show)
 
 -- | Lens accessor for the editor. See '_liveEditor'.
 liveEditor :: Lens.Lens' (AppInterpState s n) (BE.Editor s n)

lib/ghcitui-brick/Ghcitui/Brick/AppState.hs

@@ -67,6 +67,7 @@ data WidgetSizes = WidgetSizes
     { _wsInfoWidth :: !Int
     , _wsReplHeight :: !Int
     }
+    deriving (Show)
 
 {- | Application state wrapper.
 
@@ -106,6 +107,7 @@ data AppState n = AppState
     , splashContents :: !(Maybe T.Text)
     -- ^ Splash to show on start up.
     }
+    deriving (Show)
 
 newtype AppStateM m a = AppStateM {runAppStateM :: m a}